The biomedical engineering and physics core facility is intended to make the following services available to the Division of Aging: 1) A mathematical modeling and computer simulation service is provided in order to analyze the dynamics of physiological systems and to reduce the use of vertebrate animal experimentation, when possible. 2) A physiological data acquisition service provides Holter monitoring equipment and a non-invasive, continuous blood pressure recording devise for monitoring human subjects. It also loans transducers, amplifiers, and recorders for the monitoring of physiological signals during animal experiments. 3) A physiological signal processing service digitizes, displays and analyzes physiological signals such as those obtained through service #2. Special software is provided for the analysis of ECG waveforms, blood pressure waveforms, and electrophysiological signals. General purpose software is provided for performing Fourier transforms, filtering and principal component analysis, as well as for calculating new non-linear diagnostics such as Lyapunov exponents. 4) An image acquisition service provides 2-D, M-mode and Doppler echocardiograms, specializing in difficult cases, which are common among elderly subjects. This service also makes available video cameras and recorders for the study of patient gait and movement, as well as a research grade fluorescence video microscope, a laser scanning microscope, and a tandem confocal scanning microscope for cell biology projects. 5) An image processing and interpretation service provides experienced readers of echocardiographic and nuclear medicine images. The service also performs digital image processing of images such as those recorded by the image acquisition service, including image enhancement and filtering, image segmentation and pattern recognition, and three-dimensional reconstruction from microscopic optical serial sections. 6) A biomechanics and biomotion service performs stress-strain measurements using a servo-hydraulic materials test system and provides an engineering analysis of gait and movement. 7) A prototype development service makes available to investigators a small machine shop and an electronics shop. It also provides prototype bladder prostheses and custom biomaterials.